Fuel



Patented July 20, 1926.

UNITED STATES PATENT OFFICE.

THOMAS MIDGLEY, JR., OF DAYTON, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS. TO GENERAL MOTORS. CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE.

I FUEL.

R Drawing.

This invention relates to the use of lead alkyl and aryl compounds in hydrocarbon motor fuels such, for example, as kerosene and gasoline, to increase the critical compression pressure of the fuel and avoid a fuel knock in an internal-combustion engine operating at compressions above the normal critical compression pressure of the fuel. The principal object of the invention is to form with the fuel and a hydrocarbon compound of lead, a combination which burns in the engine and yields a lead compound having a relatively low fluxing action as contrasted particularly with lead oxide.

Fuel knock is a function of the fuel employed and the compression pressure used as contrasted with a mechanical knock, and the term antiknock substance as emplo ed I herein designates a compound which, w en present in the combustion chamber in relatively small quantities at the time of combustion, inhibits the fuel knock.

This combination may beefiected by employing with a tetra ethyl, tetra phenyl,

tetra methyl, tetra amyl, or other similar compound oflead in the fuel, a chlorine compound such, for example, as carbon tetra chloride or an alkyl chloride such as am l chloride, hexyl chloride or eth l chlori e,

which supplies chlorine whic combines with the-lead during combustion to form a lead-chloride compound. The corresponding iodide and bromide compounds may be employed in place of the chloride compounds. 5 A preferred method of carrying out my invention in forming this class of combination is to use a mixture (by weight) of 2 arts of carbon tetra chloride and 3 parts of ead tetra ethyl or lead tetra methyl, etc.

This mixture is added to the fuel in the storage tank of a filling station or the fuel tank of a car and fed with the fuel into the combustion chamber of an engine and I burned therein. One of the products of combustion is a lead halide such as, in the specific example given above, lead chloride.

Another method of carryingout my invention is to form a lead alkyl or aryl chemical combination with the substance which unites with the lead during combustion to form a lead compound other than lead oxide. Exam les of such com oundsare' lead diheny dibromide, lea diphenyl diiodide,

ead diphenyl dichloride, and the corresponding ethyl, methyl, and other alkyl and Application and my 1a, 1923. Serial No. 040,274

as revised by Morley and Muir and published by Longmans, Green and (30., London, England.

In' these fuels, the lead and the hydrocarbon combined therewith, form the base of the anti-knock substance which suppresses a fuel knock in a mixture formed in part by a low compression fuel such as gasoline-or kerosene and the complete compound or mixture is formed about this base. The term chemical is employed in the claims to designate an element or combination of elements present either in chemical combination with the lead or in a material not in chemical combination with the lead, the chemical being adapted to form with the lead a substantially non-fiuxing compound during combustion of the fuel. It has been found that these substances form practically nonfluxing compounds when burned.

The alkyl dihalide compounds of lead and the trialkyl monohalide compounds of lead are generally less soluble in kerosene and gasoline than the tetra alkyl compounds. Benzol and an alcohol miscible in all proportions with paraffin hydrocarbons, or mixtures thereof, may be employed to assist in blending these anti-knock compounds with the fuel. The percenta e of these blending agents employed with t e small amount of anti-knock compound to be adilg-d to the fuel, is generally not over 1% of the total gasoline for the trialkyl monohalide compounds and not over 5% of the total gasoline for the dialkyl dihalide compounds.

These proportions of the blending agents may be used for the corresponding phenyl compounds.

I claim:

1. A homogeneous composition of matter comprising a motor fuel, and an anti-knock substance for said motor fuel having a lead content and a. chemical adapted to combine with the lead during combustion of the fuel to form a lead compound having a lower fluxing action than lead oxide.

2. A homogeneous composition of matter Comprising a motor fuel, and an anti-knock substance for said motor fuel having as a relatively nonfluxinglead compound;

3; A homogeneous composit on of -malted} comprising gasoline, and an anti-knock sub stance for said motor fuel formed on a lead 1 alkyl base and having a chemical adapted to combine with the lead--duringbumingfin i an engine to forma lead-compound having a lower fiuxing "action"thany'leadoxide.

4.1 A composition ofjma ttefflcomprisinfg a 1 15 motorfuel'; fandan anti-knock substancefor said motor fuel havingas a base-a lead: c'omi;

pound and containing a'ha'logen.

0 of lead, and a halide.

6. composition of matter compi'ising a hydrocarbon fuel, an alky-l compound :of lead, and a halide. 1, A composition of matter ',comprising gasoline,""'an alliyl compoundof lead, and. a 2' chloride.

S A composition offl matt e "comprising gasoline, llld -tef l g alethylQ aild Lcaifbfon" tetra chloride.

9. A compositionof matter Comprising a 30 lead alkyl compound, and a halide.

A composition of matter vcomprising a lead alkyl compound, and a chloride.

" composition of matter zcomprising a lead 'alkyl compoundfand: ca ben tem 35 12 A composition 'of maltei I v I lead-tetra'ethyl; and carbontetra chloride; 5. A composition of matter comprising a h drocarbon fuel, a hydrooarbom Compou d In testimony whereof I hereto-aflixzmy signature." w

' THOMAS J1; 

